David Goodenough wrote: > On Friday 05 August 2005 11:57, Martijn van Oosterhout wrote: > >>On Fri, Aug 05, 2005 at 10:08:42AM +0100, David Goodenough wrote: >> >>>I was looking at an application recently which was written in Java and >>>used Postgresql as it DB. In it extensive use had been made of >>>PreparedStatements both for SELECTs and for INSERT, UPDATE and DELETE >>>statements. Some of the routines had multiple UPDATEs doing much the >>>same thing but with slightly different parameters. In the comments it >>>was stated that it was better to prepare lots of statements in advance >>>rather than build one on the spot (and then prepare it, it needed the >>>substitution) because of the optimiser. >> >>Which version of PostgreSQL was this built for? Until recently there >>was no support for server side prepared statements so it mattered not >>one wit whether you had one or a thousand prepared queries, it was all >>done by the client anyway. > > I am not sure it was originally build for PostgreSQL, but it all client side > anyway, or that its inside Tomcat and thus from PG's point of view > client side. I presume by server side you mean triggers and functions or > am I misunderstanding you? > He's saying that until recently, PostgreSQL did not support prepared queries. That feature was introduced in version 7.3 (I guess that's not very recent, but it can take a while for client code to start using the new features). So, it's possible that the "prepared queries" you're using are actually just sending a new query each time. For instance, if you connect to a 7.2 database and start doing prepared queries, surely those are done on the client side, because the 7.2 server doesn't support prepared queries. Regards, Jeff Davis ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
